/**
* @brief Allocates a DMA stream.
* @details The stream is allocated and, if required, the DMA clock enabled.
* The function also enables the IRQ vector associated to the stream
* and initializes its priority.
* @pre The stream must not be already in use or an error is returned.
* @post The stream is allocated and the default ISR handler redirected
* to the specified function.
* @post The stream ISR vector is enabled and its priority configured.
* @post The stream must be freed using @p dmaStreamRelease() before it can
* be reused with another peripheral.
* @post The stream is in its post-reset state.
* @note This function can be invoked in both ISR or thread context.
*
* @param[in] dmastp pointer to a stm32_dma_stream_t structure
* @param[in] priority IRQ priority mask for the DMA stream
* @param[in] func handling function pointer, can be @p NULL
* @param[in] param a parameter to be passed to the handling function
* @return The operation status.
* @retval FALSE no error, stream taken.
* @retval TRUE error, stream already taken.
*
* @special
*/
bool_t dmaStreamAllocate(const stm32_dma_stream_t *dmastp,
uint32_t priority,
stm32_dmaisr_t func,
void *param) {
chDbgCheck(dmastp != NULL, "dmaAllocate");
/* Checks if the stream is already taken.*/
if ((dma_streams_mask & (1 << dmastp->selfindex)) != 0)
return TRUE;
/* Marks the stream as allocated.*/
dma_isr_redir[dmastp->selfindex].dma_func = func;
dma_isr_redir[dmastp->selfindex].dma_param = param;
dma_streams_mask |= (1 << dmastp->selfindex);
/* Enabling DMA clocks required by the current streams set.*/
if ((dma_streams_mask & STM32_DMA1_STREAMS_MASK) != 0)
rccEnableDMA1(FALSE);
#if STM32_HAS_DMA2
if ((dma_streams_mask & STM32_DMA2_STREAMS_MASK) != 0)
rccEnableDMA2(FALSE);
#endif
/* Putting the stream in a safe state.*/
dmaStreamDisable(dmastp);
dmaStreamClearInterrupt(dmastp);
dmastp->channel->CCR = STM32_DMA_CCR_RESET_VALUE;
/* Enables the associated IRQ vector if a callback is defined.*/
if (func != NULL)
NVICEnableVector(dmastp->vector, CORTEX_PRIORITY_MASK(priority));
return FALSE;
}
/**
* @brief Allocates a DMA stream.
* @details The stream is allocated and, if required, the DMA clock enabled.
* The function also enables the IRQ vector associated to the stream
* and initializes its priority.
* @pre The stream must not be already in use or an error is returned.
* @post The stream is allocated and the default ISR handler redirected
* to the specified function.
* @post The stream ISR vector is enabled and its priority configured.
* @post The stream must be freed using @p dmaStreamRelease() before it can
* be reused with another peripheral.
* @post The stream is in its post-reset state.
* @note This function can be invoked in both ISR or thread context.
*
* @param[in] dmastp pointer to a stm32_dma_stream_t structure
* @param[in] priority IRQ priority mask for the DMA stream
* @param[in] func handling function pointer, can be @p NULL
* @param[in] param a parameter to be passed to the handling function
* @return The operation status.
* @retval false no error, stream taken.
* @retval true error, stream already taken.
*
* @special
*/
bool dmaStreamAllocate(const stm32_dma_stream_t *dmastp,
uint32_t priority,
stm32_dmaisr_t func,
void *param) {
osalDbgCheck(dmastp != NULL);
/* Checks if the stream is already taken.*/
if ((dma_streams_mask & (1 << dmastp->selfindex)) != 0)
return true;
/* Marks the stream as allocated.*/
dma_isr_redir[dmastp->selfindex].dma_func = func;
dma_isr_redir[dmastp->selfindex].dma_param = param;
dma_streams_mask |= (1 << dmastp->selfindex);
/* Enabling DMA clocks required by the current streams set.*/
if ((dma_streams_mask & STM32_DMA1_STREAMS_MASK) != 0)
rccEnableDMA1(false);
#if STM32_HAS_DMA2
if ((dma_streams_mask & STM32_DMA2_STREAMS_MASK) != 0)
rccEnableDMA2(false);
#endif
/* Putting the stream in a safe state.*/
dmaStreamDisable(dmastp);
dmastp->channel->CCR = STM32_DMA_CCR_RESET_VALUE;
/* Enables the associated IRQ vector if a callback is defined.*/
if (func != NULL)
nvicEnableVector(dmastp->vector, priority);
return false;
}
